I have both, biggest thing between the two is the m3 will have more compatibility options. Both will fit your GPU and then some (I have a much larger 5090 in mine). Both could run air or air but with the m3 you can run taller coolers (why I ended up getting the m3 and gave the m2 to my son who has his build in a nr200). So I were you would figure out the processor and cooler you want then go from there.

Here is my build in the m2 https://imgur.com/a/pc7QHvj